5 Buffer Yard OrdinanceCITYOF
CHANHASSEN
6~0 Gq Center D~Jve, PO Box I47
Ct~ant,assen, Minnesota 55317
Phone 612. 937, I900
General Fax 612.93Z5739
E, gi,eeri,g Fax 612.93Z 9152
h~b/ic S~6v £ax 612. 93(2524
l~b u,wu~ ci. cha,lsasse,.,m, us
MEMORANDUM
TO:
FROM:
DATE:
SUB J:
Planning Commission
Jill Sinclair, Environmental Resources Specialist
June 14, 2000
Proposed Buffer Yard Ordinance Revision
UPDATE
At the February 2, 2000, work session, the Planning Commission reviewed the
Buffer Yard Ordinance. Revisions suggested by the Commission and are noted
in italics.
BACKGROUND
In 1996, the city adopted the buffer yard ordinance as a way to effectively
transition different land uses. It has been applied to every development since that
time with good results. However, there have been recurring questions from
developers, staff and officials prompting staff to propose clarifications and
changes to the ordinance in order to clear up any confusion.
There are five issues that come up frequently and should be addressed: · How is the "plant unit multiplier" used?
· According to the ordinance, a developer is only responsible for planting
75% of the total number of plants required. Are there situations in which a
developer should be responsible for 100% of the plantings?
Can berms be substituted for shrubs or trees?
· Can required boulevard trees or reforestation plantings be counted as
buffer yard plant units?
· Why can't evergreens be counted as overstory trees?
ANALYSIS OF PROPOSED ORDINANCE AMENDMENTS
Staff has prepared a strike through and bold format to show proposed changes to
the ordinance. In addition, comments on the proposed changes are provided after
each section.
The City of Chanhassen. A sovw/n,¢ commun/t~ with ckan lakes, aua/in, schooh, a charmin~ downtown, thriving businesses, and beautiful aarks, g ~reat ,/ace to live, work,
Planning Commission
June 14, 2000
Page 2
Article XXV. Landscaping and Tree Removal
Section 20-1176 (f) (2) (c) Buffer yard requirements are stated in terms of the width of the buffer
yard and the number of plant units required per 100 linear feet of buffer yard. Each illustration
depicts the minimum buffer yard required between two uses or adjacent to a collector or arterial
right-of-way. The plant unit multiplier is a factor by which the basic number of plant materials
required for a given buffer yard is determined in accordance with the selected width of the yard.
The project developer shall be responsible for providing 75 percent of the required plantings. If
abutting property owner(s) desire to bring the buffering to 100 percent of the required buffer yard
plantings, then the adjacent property owner(s) may install the remaining 25 percent of the
required plantings on their own property. When the parcel abuts public property, such as
roads or parks, the developer shall be responsible for 100% of the required plantings.
· The proposed amendment deletes any mention of the plant unit multiplier. In the pictorial
buffer yard descriptions, the number of required trees and shrubs for each width are clearly
depicted and can be easily counted with no need for the plant unit multiplier calculations,
which seem to confuse the project developers.
· Buffer plantings along roads and parks should be 100% of the total required. Along roads
there is no room for the city, county or state to complete the remaining 25% of the plantings.
Additionally, in parks there may be many reasons why additional plantings on public property
aren't feasible.
· A commissioner recommended that the last line of the section should read "...the developer
shall increase the required number of plantings by 33%." The Commission should decide
which ending is more user-friendly and clearly represents the intent of the condition.
Section 20-1176 (f) (3) Plant material existing on a parcel which meets the buffer yard planting
requirements of location, size and species may be counted toward the total buffer yard plant
material requirement. Existing natural features such as slopes, woodlands or wetlands which
provide physical separation between developments or between a development and a collector and
arterial road may satisfy the buffering function of the required buffer yard. The plant unit
multiplier for the required plantings shall be reduced proportionally to the increase in the buffer
yard width incorporation said features. Proposed berms 3 feet and higher in the buffer yard
may be substituted for up to one-half (¼) of the required understory trees and shrubs,
depending on the length of the berm. For instance, if a berm runs the entire length of the
buffer yard, the understory and shrub plantings may be reduced by one-half.
boulevard trees or reforestation plantings required in thc buffer yard can be counted
towards required ovcrstory buffer yard plantings if there is insufficient room for both
types of plantings. If there is insufficient room for all plantings, the applicant may choose to
either plant excess materials on public property or employ a landscape density transfer.
Planning Commission
June 14, 2000
Page 3
· In any given area between a collector road and a parking lot, a project developer is required to
install landscaping for parking lots, boulevard trees and buffer yard plantings. It can be a
cumbersome design trying to fit in all the different requirements in a limited space.
a. Staff recommends that these layers be allowed to overlap; i.e. overstory buffer yard
plantings could be counted towards boulevard trees requirements.
b. Planning Commissioners recommended that all plantings be required. Excess plantings
should be put on public property or a landscape density transfer should be used.
'Landscape density transfer' will need to be defined.
· The proposed amendment allows berms to be substituted for understory and shrub plant
materials. In some situations, a berm and plantings may be more effective than plant
materials alone.
Section 20-1176 (f) (6) Canopy trees are defined as those trees specified as primary or secondary
deciduous trees or conifers in the city's subdivision ordinance. Conifers to be used as overstory
trees shall have a minimum height of S feet when planted. Arborvitae shall not be used as an
overstory tree.
Section 20-1176 (f) (7) Understory trees are defined as those trees specified as ornamental or
conifer trees in the city's subdivision ordinance. Conifers to be used as understory trees shall
have a minimum height of 6 feet when planted.
The proposed amendments include conifers as overstory or understory trees. All evergreens
in the city's approved tree list, with the exception of the arborvitae, reach at least 40 feet in
height at maturity. Staff recommends the arborvitae continue to be classified as an
understory tree.
STAFF RECOMMENDATION
Staff recommends the Planning Commission recommend approval of Buffer Yard Ordinance
Amendments to Section 20-1176. Buffer Yard Requirements by adding the language that appears
in bold and deleting the language noted by a strike-through:
Section 20-1176 (f) (2) (c) Buffer yard requirements are stated in terms of the width of the buffer
yard and the number of plant units required per 100 linear feet of buffer yard. Each illustration
depicts the minimum buffer yard required between two uses or adjacent to a collector or arterial
right-of-way. The plant unit multiplier is a factor by which the basic number of plant materials
required for a given buffer yard is determined in accordance with the selected width of the yard.
The project developer shall be responsible for providing 75 percent of the required plantings. If
abutting property owner(s) desire to bring the buffering to 100 percent of the required buffer yard
plantings, then the adjacent property owner(s) may install the remaining 25 percent of the
Planning Commission
June 14, 2000
Page 4
required plantings on their own property. When the parcel abuts public property, such as
roads or parks, the developer shall be responsible for 100% of the required plantings.
Section 20-1176 (f) (3) Plant material existing on a parcel which meets the buffer yard planting
requirements of location, size and species may be counted toward the total buffer yard plant
material requirement. Existing natural features such as slopes, woodlands or wetlands which
provide physical separation between developments or between a development and a collector and
arterial road may satisfy the buffering function of the required buffer yard. The plant unit
multiplier for the required plantings shall be reduced proportionally to the increase in the buffer
yard width incorporation said features. Proposed berms 3 feet and higher in the buffer yard
may be substituted for up to one-half (%) of the required understory trees and shrubs,
depending on the length of the berm. For instance, if a berm runs the entire length of the
buffer yard, the understory and shrub plantings may be reduced by one-half. Any
boulevard trees or reforestation plantings required in the buffer yard can be counted
towards required overstory buffer yard plantings if there is insufficient room for both
types of plantings. _
Section 20-1176 (f) (6) Canopy trees are defined as those trees specified as primary or secondary
deciduous trees or conifers in the city's subdivision ordinance. Conifers to be used as overstory
trees shall have a minimum height of 8 feet when planted. Arborvitae shall not be used as an
overstory tree.
Section 20-1176 (f) (7) Understory trees are defined as those trees specified as ornamental or
conifer trees in the city's subdivision ordinance. Conifers to be used as understory trees shall
have a minimum height of 6 feet when planted.
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